a, The snapshots showing the ‘Virtual 4C’ (converted from Hi-C datasets) among bivalent genes in 8-cell, ICM, E6.5Epi, E6.5VE, mESC, and fibroblast. The enrichment of H3K4me3 and H3K27me3 in E6.5Epi (n=2) and E6.5VE (n=2) are shown below. Magnified views of interactions between bivalent genes are also shown. b, Heatmaps showing the inter-chromosomal interactions between chromosomes 2 and 11. Boxes show the zoomed-in views of interactions between Dlx, Hoxd cluster (chr2) and Hoxb clusters (chr11). A UCSC genome browser of H3K27me3 enrichment in wild-type E6.5Epi is shown on the top to indicate the positions of Polycomb targets.